Concrete pipe-forming apparatus having outer form and core members arranged to rotate at different speeds



Aug. 5, 1958 H. x. ESCHENBRENNER 2,845,682

CONCRETE PIPE-FORMING APPARATUS HAVING OUTER FORM AND CORE MEMBERS ARRANGED TO ROTATE AT DIFFERENT SPEEDS 2 Sheets-Sheet 1 Filed May 28, 1954 INVENTOR /7.X. fsc-fzevzfirenizev- BY $W ATTORNEY Aug. 5, 1958 -H. x. ESCHENBRENNER 2,345,682

CONCRETE PIPE-FORMING APPARATUS HAVING OUTER I FORM AND CORE MEMBERS ARRANGED TO ROTATE AT DIFFERENT SPEEDS Filed May 28, 1954 2 Sheets-Sheet 2 INVENTOR A X. 56726725787272 e7 WWW ATTORNEY 2,845,682 7 Patented Aug. 5, 1958 CONCRETE PIPE-FDRR HNG APPARATUS HAVING OUTER FORM AND GORE MEMBERS AR- RANGED T ROTATE AT DIFFERENT SPEEDS Hector X. Eschenhrenner, Columbus, Ohio; Hector E. Eschenbrenner, executor of the estate of said Hector X. Eschenbrenner, deceased Application May 28, 1954, Serial No. 433,053

1 Claim. (Cl. 25-30) This invention has for one of its leading objects to provide an improved machine for forming concrete and other ceramic bodies of hollow, generally cylindrical form, such as pipe, culverts and the like, and to construct the machine so that it embodies, in relatively spaced, vertically disposed, concentric order, a cylindrical outer form member and an inner core member and wherein improved means are provided for independently supporting said members for rotation at relatively dilferent rates of speed.

For a further understanding of the invention, including additional objects, features and advantages thereof, reference may now be had to the following detailed description and the accompanying drawings which set forth a single, presently preferred, pipe-forming machine embodying the mechanical operating principles of my invention. In said drawings:

Figure l is a central vertical sectional view taken through the pipe-molding machine of the present invention.

Figure 2 is a fragmentary vertical sectional view taken through the lower part of the machine, the figure being on a somewhat larger scale than that used in the preceding figure, and disclosing in greater detail the construction of the rotary turntable of the machine and its inner core, outer form and center pin members.

Figure 3 is a horizontal sectional view taken along the line 33 of Figure 1, and Figure 4 is an enlarged, detailed, horizontal sectional view taken on the line 4--4 of Figure 2.

At present two general types of upright rotary concrete pipe-forming machines are to be found in commercial use. First, such machines are constructed to embody a cylindrical outer form member adapted to be mounted upon and rotatably carried by an associated horizontally disposed rotary turntable, there being employed in connection therewith an inner, axially extending, relatively stationary core member which is vertically removable from its position within the outer form member through its association with a non-rotatable elevating beam mechanism.

The first type of machine is the one most commonly used in concrete pipe molding. In its operation, a moldable cementitious mix is tamped within an annular chamber formed between the outer form and the inner core members while the outer form member and the mix are rotated around the relatively stationary inner core member. While in machines of this specific type, the inner core member is usually provided with outwardly disposed friction liners, nevertheless the liners become worn and damaged after relatively short periods of use; a condition attributable to the friction developed by the rotation and abrading of the raw mix against and around the outer surfaces of the core member during machine operation. y

In the second type of such machines, as used in the formation of concrete pipe, the same embody the outer form member and supporting turntable mechanism therer it for, but each machine of the second type provides for rotation of the inner core member in unison with the outer form member, the turntable mechanism and the deposited mix. In this second type, the mix is usually compacted within the annular pipeforming chamber and thereby tendsto bind effectively the inner core member with the outer form member to that said members will rotate at the same speed.

While the second type of machine reduces greatly wear on the outer surfaces of the core members thereof, the same does not provide, as does the first type for a desirable churning action on the part of a mix positioned between said members, nor does the second type of machine function to trowel or smooth the inner surfaces of pipe formed therein. Of course, in the first or stationary core type of machines, the rotatable outer form member and stationary inner core member provide for mix-churning and surface trowelling or smoothing, but

is objectionable because of excessive wear on the part of the mix-contacting surfaces of the core member thereof.

Accordingly, the instant construction is directed to an improvement upon these two prior types of machines by providing novel means for supporting and rotating the outer form and inner core members to produce a differential speed of rotation therebetween, thus imparting to the mix a desirable churning and trowelling action and at the same time greatly reducing frictional wear and abrasion .upon the outer surfaces of an associated core member, or the lining, if any, arranged thereon.

This differential in the speed of rotation between the inner core and outer form members is attained in an advantageous manner with the use of the reduction gear mechanism shown in the "drawings. In the latter, the number 1 designates the usual rotatable turntable found in concrete pipe-forming machines, the same being formed on its undersurface with depending annular gear teeth 2 which are spaced slightly inwardly from the outer periphery of the turntable. These teeth are engaged by those of a pinion 3 which is shown as being fixed on the inner end of a power actuated drive shaft 4. The turntable 1 is provided at intervals with peripherally spaced upstanding brackets or other equivalent formsupporting members 5. These members are adapted to receive upon the upper surfaces thereof the lower circular base ring or flange 6 of an upright, cylindrical, outer form member 7. The ring 6 is held in its seated position on the upper surfaces of the brackets 5 and maintained in fixed driving relationship therewith through the use of any suitable means, such as the locking dogs 8.

In a usual manner, the outer form member 7 has its lower end closed for mix reception by means of a circular pallet 9. The configuration of this pallet is such as to include an annular substantially vertically extending web 10 which terminates in an outwardly directed horizontal and annular upper rib 11 and a corresponding but inwardly directed lower rib 12, the pallet being supported in its operative position, as viewed in Figure 1 of the drawings, by the resting of the rib 11 on a seating shoulder 13 which projects rigidly and inwardly from the form member 6. Internally, the pallet 9 is devoid of spokes, webs or radial formations.

The machine further includes an. upright, rotative inner core member 14 of hollow cylindrical construction. The top of this core member has seated thereon a circular top plate 15, the latter being provided at its outer circumference with a depending positioning and molding flange 16. It will be observed that an annular, vertically extending, mix-receiving chamber 17 is formed as usual, between the outer cylindrical surfaces of the core member and the adjacent inner surfaces of the form member for the reception of a formative, cementitious body of pipe=molding material, as indicated at 18, said material entering the chamber by a chute 19 or its equivalent. The flange 16 of the top plate functions to mold a circular inwardly disposed socket 20 in one end of each pipe body 18 molded in the machine, While the web 10 and its rib 11 function to mold an outwardly disposed annular recess 21 in the opposite end of the pipe body, forming thereon a spigot extension 22.

The top plate 15 carries a short, rigid and upwardly extending annularly grooved stud 23, the circularly flanged lower end 24 of the stud being bolted or otherwise firmly fastened to the top plate in coaxial relation with the core member 14. The annular groove in the body of the stud receives an inturned flange 24 formed on the lower part of a bracket 25 which constitutes the upper element of a swivel joint. The bracket 25 is suitably fastened as at 26 to the underside of a horizontally extending vertically movable cross beam 27 of the machine. In any suitable manner the opposite ends of the cross beams are guided for vertical movement in connection with relatively spaced, stationary, vertical frame beams 28. The cross beam 27 and the core member 14 swivelled thereto may be moved in a guided manner vertically and axially with respect to the outer form by means, for example, of the hoisting pulley and cable arrangement shown at 29.

The rigid horizontal wall or plate 30, which closes the bottom of the core member, is formed in its central region with an annular hub 31 which is adapted to receive the upper end portion of a center pin 32 extending axially and upwardly from the turntable 1. The center pin is joined for rotation in unison with the turntable by means of a locking key 33 which, as shown in Figure 4, extends transversely through an opening 34 formed in the body of the pin and beyond the same to provide projecting ends which are disposed in recesses 35 formed in the upper surface of the turntable, The lower end of the pin 32 is disposed in an axial opening 36 of the turntable, the pin extending through andb'elow the opening 36 for reception in a pocket 37 formed in the axial upper part of a vertically depending shouldered turntable stud 38. This stud, in turn, as shown in Figure 1, is received in the base 39 of a supporting sleeve 49 carried by the stationary base frame 41 of the machine.

The construction provides for vertical removal of the center pin 32 for cleaning and disassembly purposes, but with the pin 32 and its key 33 positioned in the recesses 35 of the turntable, the pin rotates positively with the table. hub 42 of an upper disk member 43 carried by a circular gear housing 44. The latter includes a lower disk member 45 which is disposed in spaced parallel relation with the upper disk member. The hub 42 of the upper disk member and the corresponding hub 46 of the lower disk member are free to rotate about the pin 32 and may be equipped with a bearing sleeve 47 and the washers 48, as shown in Figure 2. The weight of the inner core member when in operation may be partly bourne by the swivels 23, 24 and 25.

The pin 32 has keyed to the intermediate portion thereof within the gear housing 44, a first pinion gear 49, the teeth of which extend radially outwardly into the gear chamber 50 of the housing 44 in order that they may mesh with those of idler gears 51 rotatably supported in the housing for rotation about stationary axles 52. The idler gears 51, in turn, mesh with similar gears 53 and the latter have their teeth in mesh with the internal teeth of an enlarged gear ring 54 which forms a part of the housing 44 and is fastened to and spaces the top and bottom disk members 43 and 45. At spaced intervals around its outer circumference the housing 44 is formed Rotatably mounted on the pin 32 is the axial with upstanding studs 55, which have their upper ends received in sockets provided in the lower ends of bosses 56 rigidly depending from the bottom plate 30 of the core member 14.

In the operation of the machine so formed, rotation of the turntable 1 and the outer form member supported thereby serves to rotate the vertical pin 32 and the gear 49 which it carries. This rotation is imparted through the idler gears 51 and 53 to the gear ring 54 of the housing but at a reduced rate of speed as compared with the R. P. M. of the turntable. Since the gear ring 54 rotates the core member 14 through the studs 55 and the turntable rotates the outer form member in unison therewith, it follows that said members while turning in the same direction, rotate relatively to each other, so that churning of the cementitious mix takes place in the molding chamber 17, together with trowelling of the inner surfaces of the molded pipe. It will be understood that the proportion of speed reduction is not critical and any suitable gearing or motion-transferring mechanism may be employed to obtain the desired relative speed of rotation between the outer form and inner core members. It will also be noted that the gearing disclosed provides for positive and precise relative rotational speeds on the part of the form and core members, so that the speed of the outer form member cannot be transmitted to the core member through compaction of the mix in the molding space present between said members. The construction is simple, rugged and positive and is capable of withstanding the severe service necessary in the operation of machines of this kind.

While I have set forth a single preferred form or embodiment of my improved pipe-forming machine, and have defined the same in considerable detail, nevertheless, it will be understood that the defined embodiment is illustrative merely of but one of several possible different forms of a machine in which my invention may be incorporated, and I, therefore, reserve the right to employ all such variations or modifications thereof which may be said to fall fairly within the scope of the following claim.

I claim:

A turntable for concrete pipe-forming machines of the type embodying relatively concentrically spaced and relatively rotatable outer form and inner coremembers, said turntable comprising a generally circular, horizontally arranged body; an annular ring gear carried by said body and arranged to be driven to impart rotation to said body; outer form-supporting means carried by and extending upwardly from said body to removably receive and support for rotation with said body the outer form member of a concrete pipe-forming machine; pin means projecting upwardly and axially from said body and connected to be driven in rotation therewith; a substantially flat circular gear box rotatably supported on the central upper surface of said body for rotation about said pin means and disposed radially inwardly from said outer form-supporting means; speed-reducing gearing arranged in said gear box and drivingly connected with said pin means for rotating said gear box in unison with but at a slower speed than said turntable body; and means carried by said gear box detachably supporting the inner core member of an associated concrete pipe-forming machine for rotation in unison with said gear box.

References Cited in the file of this patent UNITED STATES PATENTS 550,089 Armand Nov. 19, 1895 586,569 Sherman July 20, 1897 931,972 Thomas Aug. 24, 1909 2,606,354 Jackson Aug. 12, 1952 

